This invention relates to window structures of the type in which a window element slides along a support frame between open and closed positions and which also provides the facility for pivoting the window element in the support frame, e.g. for cleaning purposes. The invention is an improvement in or modification to the invention disclosed in applicant's prior U.S. Pat. No. 4,337,597, the disclosure of which is incorporated herein by reference in its entirety.
In accordance with the patented structure, a sliding window element is located, top and bottom, in channel-like tracks in a surrounding frame, the tracks constraining the window element for lengthwise sliding movement along the frame. The top track is fixed and has a lengthwise slot through which a headed stud extending upwardly from the window element projects, with the head of the stud being confined in a space above the slot. The bottom track can be raised and lowered in the frame by cam devices at opposite ends of the track. When the bottom track is raised, the window element is confined by the tracks for lengthwise sliding. However, when the cam devices are operated to lower the bottom rack, the window element is also lowered, and freed by the tracks for rotation about the headed stud which is retained by the slot in the top track. When the window element is realigned with the tracks, the bottom track can again be raised, reconfining the window element in the tracks to lengthwise sliding.
For a window structure of the above type, the present invention provides an alternative form of raising and lowering mechanism for the bottom track, and an alternative suspension assembly between the window element and the top track.